1. Field of the Invention
This invention relates to conduit outlet fittings for electrical connections or the like and, more particularly, to a conduit outlet fitting coated with one or more protective materials.
2. Description of the Prior Art
The use of conduit outlet fittings, also known as junction boxes, for making electrical connections or the like is well known. A conduit outset fitting typically has a hollow, open-topped base or body with one or more conduit openings therethrough. The conduit openings are typically internally threaded. Various electrical conduits are connected to the body and appropriate electrical connections between the conductors carried in the conduit are made within the interior of the body. The open top of the body is then closed by a complementary lid or cover secured thereto to enclose the electrical connections therein and prevent the connections from being contacted or damaged. Examples of prior art conduit outlet fittings are shown, for example, in U.S. Pat. Nos. 1,706,811; 2,800,247; 3,394,509; 3,430,799; 3,910,448; 4,699,293; 4,896,784 and 5,147,980.
In some environments, particularly in combustible, corrosive or other hazardous environments, it is advantageous to provide a protective coating on at least all exterior surfaces of metal, typically galvanized steel or aluminum, conduit outlet fittings and all conduit attached thereto. The protective coating can be polyvinyl chloride (PVC) or other polymeric materials. Prior art patents in this area include U.S. Pat. Nos. 3,724,706 and 3,434,900. Robroy Industries, Inc., the assignee of the present application, markets a line of PVC coated conduit outlet fittings, conduit and related products under the PLASTI-BOND RED.RTM. trademark. PVC coated conduit outlet fittings, conduit and related products are sold by Occidental Coating Company and Ocal Inc. under the name OCAL-BLUE.
While the prior art coated outlet fittings provide good protection of the product in various hazardous environments, there are several problems with these designs which have not yet been addressed.
In the coated conduit outlet fittings sold by Robroy Industries, Inc., as reflected in U.S. Pat. No. 3,724,706, a seal is provided between the body and the cover attached thereto. The body has an outwardly extending, flat seal formed in the coating material, while the cover has a similarly shaped, outwardly extending, downwardly tapered seal formed in the coating material. While this arrangement provides for an adequate seal or joint between the cover and the body, and a protective seal for the interior of the body, this seal design has a drawback in that under certain circumstances corrosive or other materials can travel past the seal and penetrate between the protective coating and the outer surface of the body or cover and cause corrosion thereof which forces the protective coating to separate from the underlying metal product. In addition, the taper of the cover seal exerts an outward force on the body seal which tends to push the body seal and coating away from the body. While the OCAL-BLUE conduit outlet fitting has a flat seal which extends partially over the body and cover and provides some additional protection for the exterior surfaces beneath the protective coating, it is difficult to consistently manufacture complementary seals on the body and cover to provide a tight seal over the entire periphery of the open top of the body. In addition, it is difficult to properly install and align the coated cover onto the coated body of the OCAL-BLUE product.
Therefore, it is an object of the present invention to provide a coated conduit outlet fitting which minimizes or prevents corrosion between the coating and the underlying metal material. In addition, it is an object of the present invention to provide a coated conduit outlet fitting with a significantly improved seal between the cover and the body. It is a further object of the present invention to provide an improved seal for a coated conduit outlet fitting which also allows the cover to be readily positioned and aligned onto the body so that the cover can be quickly and securely connected to the body.